1. Field of the Invention
The present invention relates to a semiconductor device and a driving method thereof. In particular, the present invention relates to a semiconductor device, a display device, a liquid crystal display device, or a light-emitting device which includes a driver circuit formed over a substrate over which a pixel portion is formed; or the driving method thereof. Alternatively, the present invention relates to an electronic appliance including the semiconductor device, the display device, the liquid crystal display device, or the light-emitting device.
2. Description of the Related Art
In recent years, large display devices such as liquid crystal televisions have been actively developed. In particular, a technique to form, using a transistor including a non-single-crystal semiconductor, a driver circuit such as a gate driver circuit over a substrate over which a pixel portion is formed has actively developed because the technique greatly contributes to the reduction in manufacturing cost and the improvement in reliability (see Patent Document 1 for example).